Three-Quarters Of World Will Experience Deadly Heat Waves By 2100

With all the furore surrounding Trump’s decision to pull America out of the Paris agreement – and the global reaction to it – the actual science of climate change has fallen into the background as of late. So let’s have a look and see what the world’s top scientists are saying about it now.

Peeking through a new Nature Climate Change study, it’s plain to see that a future with unchecked global warming is still going to be a pretty awful one. Specifically, if no serious action is taken to drawdown the planet’s greenhouse gas (GHG) emissions, then nearly three-quarters of the world’s population will experience life-threatening heatwaves by 2100.

“Heat wave” has a few different definitions, but a good way to think about it is if the temperature range for a few days or weeks in a certain location is found to be constantly in excess of the average. These heat waves bring with them droughts, wildfires, and an increased risk of communicable disease contraction – but the heat stress itself can also cause organ failure.

Although deaths in certain demographics during heat waves are always expected – those with health conditions, the elderly, and so on – recent heat waves have seen more deaths than would be expected, and it’s suspected that the length and intensity of them have both increased quite dramatically as of late.

This study examined papers from 1980 to 2014, and found that there were 783 cases of “excess human mortality” associated with heat waves within 36 different countries. Finding out the threshold in which excessive deaths occur, the team – led by the University of Hawai’i at Mānoa – noted that at least 30 percent of the world’s population currently experience conditions above this threshold for at least 20 days per year.

A map of 1980-2014 relationships between heat and mortality (red) and where specific heat spikes have been registered (blue). Mora et al./Nature Climate Change

The team then extrapolated their data and found that even with a drastic reduction in GHGs, 48 percent of the world would experience these deadly conditions by the end of the century. If no action is taken – say, if the Paris agreement fails and isn’t replaced – 74 percent of the global population will suffer these excessive conditions by 2100.

By then, the planet will be home to roughly 11.2 billion people, which means that 8.3 billion of them will experience potentially fatal heat waves for at least three weeks a year. As previous studies have revealed, those living in the Middle East and sub-Saharan Africa will be the most affected, but the US – as just an example – will not escape the proverbial (or perhaps literal) flames.

If you live in America and this concerns you, then don’t worry – you might be one of the lucky states to be underwater instead by the century’s end.